Like issues raised by eco-warriors showing violent manner possibly (13)
I believe the answer is:
Here is my best explanation:
'like issues raised by eco-warriors' is the definition.
'violent manner possibly' is the subsidiary indication.
'possibly' indicates an anagram.
'violentmanner' is an anagram of 'environmental'.
'showing' is the link.
(Other definitions for environmental that I've seen before include "Pertaining to the surrounding world", "Green" and "To do with one's surroundings".)